Income Taxes - Income Tax Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Income Tax Expense
Expected provision at federal statutory tax rate	$ 61,104	$ 42,991	$ 7,062
State and foreign tax expense, net of federal benefit	3,726	2,255	413
Interest and dividend on preferred stock	0	710	1,612
Change in valuation allowance	0	0	(65,248)
Meals and entertainment	649	469	315
Fines and penalties	84	(36)	9
Federal credits	0	(103)	(156)
Adjustment to deferred tax assets and liabilities	(3)	(3)	3,486
Other	564	100	211
Total income tax expense (benefit)	$ 66,124	$ 46,383	$ (52,296)